[amsat-bb] Re: Satellite tracking programming ideas

Anthony Monteiro aa2tx at comcast.net
Thu Jan 31 19:17:11 PST 2008

At 10:57 PM 1/30/2008, Phil wrote:

>I've been thinking some more about this serial problem and wondering if the
>radio might be at fault or, more likely, that I should be doing something
>read frequency commands.
>If I read the frequency once per second while spinning the tuning knob,
>occasionally I'll see an incorrect value. That same value persists until
>the knob is moved again. I can see the problem but not the answer.

Hi Phil,

Here are a few suggestions.

1. Try putting a loopback plug instead of the radio (TXD to RXD) and sending
contiguous 256 byte blocks. Use an incrementing pattern so you can see if
there are any errors as they come back in. You should be able to do 
this indefinitely
(i.e. test it for several hours) with no errors

2. Are you using 4800 bps, 8 data, no parity, 2 stop bits?

3. Are you sending the 5 byte commands contiguously (i.e. loading up 

4. Do you check for any UART errors that might be detected?

If I can think of anything else, I will let you know.

Tony AA2TX

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